The present invention relates generally to an airliner passenger seat design, and more particularly, to a spring loaded seat bottom movable between a stationary position during taxi, take-off and landing and a freed position during flight where one or more of a leading edge and a trailing edge of the seat bottom can move up and down, deflecting to different levels according to the downward load applied thereto.
The design of the seat bottom, or seat pan, of an economy class airliner seat is heavily governed by the requirement to pass a series of dynamic tests that form part of the seat certification process. The structure of the seat has to withstand extremely high loads, limit deflection under load, and do so at the minimum weight. To provide comfort, the seat bottom can be formed of a movable structure that can change position and angle according to the reclined position of the seat back. To further enhance comfort, the seat bottom can be constructed from a flexible diaphragm that is securely fastened to the seat bottom structure and covered with foam cushioning.
Passengers are required to be in an upright sitting position during taxi, take-off and landing (TTOL). During flight the sitting position requirements are relaxed. As such, the seat back of most seats is able to recline to a degree to enhance comfort. In premium class seats, the seat back has a greater range of motion and the seat back and seat bottom can be linked such that reclining the seat back changes the angle and/or position of the seat bottom. In economy class seats, the seat bottom is usually fixed in one position regardless of the reclined position of the seat back.
With either seat type, a fixed sitting position becomes uncomfortable over time. Therefore, what is needed is a seat bottom compatible with a reclining seat back that can be held stationary during TTOL to achieve a fixed, upright sitting position, and released during flight to increase body movement, improve blood flow and enhance cushioning.